This invention relates to picture archiving and communications systems, and more particularly relates to techniques for handling faults in the databases of such systems.
Picture archiving and communication systems (PACS) employ databases for cross-referencing examination sequences, images, transactional data, physician references, patient references, etc. Transactional data may include exams ordered or available, exams viewed and dictated, etc. Currently the systems operate with no backup of the data, other than conventional periodic tape back up. As a result, there is no way for the systems to continue operation immediately in the event that there is a hardware failure. In addition, data recently put into the system may be lost. This invention addresses these problems and provides a solution.
The preferred embodiment is useful in a picture archiving and communication system for providing a fault tolerant database. In such an environment, transaction data to be added to the database is provided, preferably by work stations. The database is stored in a primary storage system and also is stored in a secondary storage system. First connections enabling the transfer of the transaction data to the storage system are established. The transaction data is transferred to the primary storage system along a first path, and then is stored in the primary storage system, preferably by a first server. At time intervals, transaction data is read from the primary storage system and transferred for storage in the secondary storage system, preferably along a network. The transaction data then is stored in the secondary storage system, preferably by a second server. Second connections are established enabling the transfer of the transaction data to the secondary storage system without first storing the transaction data in the primary storage system in the event of a failure of the database stored in the primary storage system or the first server. By using the foregoing techniques, a security back up can be provided, as well as the cross checking of posting to parallel databases.